1. Field of the Invention
The invention relates to a device for repeated, automatic metering of doses of a powdered cleaning agent or detergent in water-conducting or carrying cleaning machines, in particular household dishwashers and household washing machines, including a detergent holder with an outlet opening above a metering and dispensing device being equipped with at least one indentation for receiving individual doses of a powdered detergent that are fed into a processing vessel of the water-conducting cleaning machine.
In known water-conducting cleaning machines, in which powdered detergent is dispensed for the cleaning process, particularly in household dishwashers or washing machines, a detergent holder is filled manually by the user before each cleaning operation. Due to the many manipulations the user must make, such a filling process is inconvenient. Another disadvantage of the known appliances is that exact metering of the detergent to suit the particular intended use is achievable only with great difficulty. Yet another disadvantage of the known appliances is that when the detergent holder is filled, detergent can spill out of the holder and thus is wasted.
In order to avoid those disadvantages, there is a demand in the market for machines in which the delivery of exact doses of detergent for each cleaning operation is effected automatically and repeatedly, so that optimal cleaning action is achieved while simultaneously lowering energy consumption and the burden on the environment.
Such demands are met in known machines by using large-capacity detergent holders that are capable of automatically and repeatedly supplying exact, predetermined doses of detergent for each cleaning operation. However, the known configurations for automatic, repeated feeding of doses of detergent require complex devices that can only be manufactured industrially at major cost and that are practically never consistently reliable, since the highly hygroscopic powdered detergent undergoes a change as a result of the moisture that penetrates the detergent holder of the dispenser from the processing vessel of the cleaning appliance. The detergent holder, which is disposed in the interior of the cleaning machine, is exposed to moisture which enters through the required existing ejection opening during the cleaning process, so that powdered detergent contained in the detergent holder often clumps together. The result is that the function is impeded, and moreover clumps are difficult to remove from the detergent holder of the dispenser. Clumping of the powdered detergent is a serious disadvantage, which in the worst case can cause a change in the volume of a dispensing chamber or even the complete blockage of the dispenser. Moreover, powdered detergents have a strong scouring action, and the escape of detergents into ducts, bearings and so forth of the dispenser can be effectively prevented only by using complicated and expensive seals.